The complete mitochondrial genome of the dusky shark Carcharhinus obscurus

Abstract

The dusky shark Carcharhinus obscurus is economically important but vulnerable to overharvesting. The complete C. obscurus mitogenome was assembled from approximately 1 million whole genome shotgun sequences using a combination of reference mapping and de novo assembly (mean coverage 59x). This resulted in a 16,706 bp double-stranded circular mitochondrial sequence. Following the consensus vertebrate mtDNA genome, it comprises 13 protein-coding genes, 22 transfer RNAs, two ribosomal RNAs and has 2 non-coding areas. The A+T (56.9%) versus G+C (43.1%) composition confirmed an A+T bias previously noted for sharks. This genome is the first for the speciose Carcharhinus genus and provides a valuable resource for studies of shark molecular systematics, phylogeography, conservation genetics, and stock structure.

Keywords::

• Carcharhinus obscurus
• mitochondrial genome
• 454 sequencing
• de novo genome assembly
• de novo genome annotation

Declaration of interest: The authors report no conflicts of interest. The authors alone are responsible for the content and writing of the paper. This work was supported by Fisheries Research and Development Corporation (FRDC) grant (2010/062) to Fisheries New South Wales (NSW) on behalf of the Australian Government, plus the NSW and Queensland governments.